This application claims priority from PCT Application Serial No. PCT/CN01/00536, filed Mar. 28, 2001, entitled xe2x80x9cWireless Suspension Salvage Methodxe2x80x9d, which is incorporated herein by reference in its entirity.
The present patent relates to wireless suspension salvage technology in the hard disk industry. In particular, it relates the methods of salvaging head gimbal assembly with damaged sliders.
This invention relates to a wireless suspension salvage methods used in a hard disk storage system or the like.
With increasing use of multimedia, Internet and therefore computers, demands for larger and faster data storage devices continue to grow, making the magnetic recording industry a dynamic and fast-growing sector. Magnetic recording through hard disks remain the most commonly used among the currently available storage devices in the market: floppy disks, magneto-optical disks and magnetic tapes.
As the size of the storage devices becomes smaller, the slider also needs to be produced with higher density. Lower assembly yields coming from the wafer manufacturers translate into economic burden to the manufacturers. In order to be more efficient and to save material loss, there is a need to develop a method to salvage suspensions, one of the main parts on a head gimbal assembly (xe2x80x9cHGAxe2x80x9d).
A hard disk drive consists of a motor, spindle, platters, read/write heads, actuator, frame, air filter, and electronics. The heads are bonded to a metal suspension (or head arm) which is a small arm that holds the head in position above or beneath a disk. A head and a suspension combined forms a head gimbals assembly or HGA. The HGA""s are stacked together into a head-stack assembly, which is propelled across the disk surface by the actuator. Since the size of a hard disk is only a few inches long, it could be imagined that the length of a head gimbals assembly is no more than a few centimeters.
Structure of the HGA
Traditionally, the suspension, or a suspension assembly, in a HGA consists of a slider, a suspension bonding pad, four gold balls, and UV epoxy. The slider is mounted on tongue of the suspension with UV epoxy, and 4 gold balls are welded on both of the slider and the suspension bonding pad by ultrasonic oscillation to ensure the electrical circuit connection between the slider and the suspension connection.
Several problems are inherent in the traditional approach:
1) Gold balls need to be bonded to the slider pad and the suspension pad to ensure electrical circuit connection at the head assembly level; consequently, it is difficult to separate slider and suspension without causing damages to the suspension.
2) Slider and suspension are bonded together using UV epoxy, causing additional difficulties in removing slider without causing damages to the suspension.
3) It is difficult to remove the residue epoxy on suspension tongue completely.
Therefore, there is a need for a novel method to salvage the suspension from a HGA with defective slider.
This invention relates to methods for salvaging wireless suspensions from a damaged head gimbal assembly. The slider in a head gimbal assembly is removed by horizontal twisting or vertical lifting of a pair of metal tweezers. The UV epoxy used for bonding is removed by high temperature provided by a heat gun and/or by immersion in a solvent. The gold balls from the head gimbal assembly may be separated from the damaged slider by a vertical separation, or be removed with a horizontal cut. The gold balls, if removed, can be removed either before or after the slider is removed from the head gimbal assembly.